In a historic vote in the National Assembly, Quebec has become the first province to legalize doctor-assisted death as part of comprehensive end-of-life legislation.

Bill 52, An Act respecting end-of-life care, received broad support on Thursday from nearly 80 per cent of MNAs. Quebec Premier Philippe Couillard allowed his caucus to vote according to their conscience. The 22 MNAs who voted against were all Liberals, including 10 cabinet ministers.

The legislation outlines the conditions in which a terminally ill adult patient who is of sound mind may request continuous palliative sedation that would lead to death. Patients would need to have an incurable illness and be in “an advanced state of irreversible decline in capacities.” They would also have to be in constant and unbearable physical and psychological pain that doctors would view as impossible to relieve through medication.

The procedure for making the request would be supervised by the attending physician and approved though consultation with the hospital’s medical team. And, finally, a patient could at any time withdraw a signed request for medical aid in dying.

The controversial issue is being widely discussed across the country.

The Supreme Court of Canada is taking another look at whether Criminal Code provisions against assisted dying violate the rights of the gravely ill. It is expected to rule in the fall. The B.C. Civil Liberties Association brought that case after the federal government successfully appealed a lower court ruling that those rights were indeed being transgressed and gave Parliament a year to rewrite the law.

Meanwhile, Conservative MP Steven Fletcher has introduced two private members bills that, together, would allow doctors to help people die in a restricted set of circumstances.

Opponents to Quebec’s law, especially religious groups and even the federal government, have threatened in the past to mount court challenges, arguing that assisted suicide and euthanasia are illegal under the Criminal Code.

“It is for the courts to decide if any province is legislating within its jurisdiction,” Mary Ann Dewey-Plante, a spokeswoman for federal Justice Minister Peter MacKay, said on Thursday. “It is our government’s position that the Criminal Code provisions prohibiting assisted suicide and euthanasia are constitutionally valid, and in place to protect all persons, including those who are most vulnerable in our society.”

Quebec Health Minister Gaétan Barrette said the province received advice from legal experts, including the Quebec Bar Association, indicating it could win a court challenge. Quebec says its bill cannot be legally defined as euthanasia or assisted suicide because it extends health-care services, which are provincial jurisdiction.

Quebec’s vote came after more than four years of often heart-wrenching deliberations – a process Mr. Barrette thinks the rest of the country will soon undertake.

“Canada will not be spared the debate. At some point, they will have to face it. But I believe that support for an initiative like this one will not be uniform across the country,” he said.

The Canadian Medical Association, which opposes assisted suicide and euthanasia, has engaged in a nationwide consultation about end-of-life issues and will reveal the results on Tuesday. The Canadian Medical Association Journal has said in an editorial that “Canadians need to engage in a broad dialogue” about whether terminally ill patients should have the right to a “therapeutic homicide.”

Parti Québécois MNA Véronique Hivon, who spearheaded the bill when she was a minister in the PQ government, said the legislation should not be viewed as “medical aid to die” but “end-of-life care.”

Mr. Couillard, who was a neurosurgeon before entering politics, said his encounters with dying patients convinced him people do not want to die, but they do want to end their suffering.

“Not once did patients tell me that they wanted to die. But they often told me that they no longer wanted to endure the pain and wanted to go to sleep,” he said.

He applauded changes to the bill adopted in committee hearings, especially those allowing doctors to object to administering medications that would lead to death. “Without such changes, I would not have been able to support the bill,” Mr. Couillard said in the National Assembly.

The law will take effect at the end of 2015, so hospitals and physicians have time to meet administrative requirements and set up clinical protocols.